Looks like your best trainees are PF/C. So concentrate on that with 2 position training of big men. Pick your best 6 trainees and make sure your 18-21 year olds are your main focus, but it's ok to use your 23 year old in this cycle as he looks like he might be your best player and it will help you win some games to keep him in the cycle. Don't use your 32 year old center you bought in your training. And also the 19 year old MVP guard you bought seems like his starting skills are too low to really worry about training - but I can't see his skills so you may disagree. But he won't train well in this cycle. But if you like him, then you could include him in training and next season if you get a couple of good guards in the draft, then you can switch next season to guard training and this 19 year old will have some decent secondary skills already built up. Good luck.